Cushioned bathroom articles, such as bathtubs, shower stalls, sinks and the like, are known in the prior art as being formed from a laminated structure having a flexible polymeric layer, typically of vinyl, a base, typically made of a fiberglass-reinforced, polyester resin, and a cellular foam sandwiched between the flexible polymeric layer and the base. Such cushioned bathroom articles are comparable in appearance with conventional steel or iron, porcelain-coated bathroom receptacles, and the foam provides improved thermal and acoustic insulation over such conventional receptacles. Moreover, when this composite structure is applied to bathtubs, the combination of the flexible polymeric outer layer and the foam makes it unlikely for anyone to slip in the bathtub and cushions any fall that does occur.
For a number of reasons, such cushioned bathroom articles have not found widespread acceptance. Perhaps the most important of these reasons is the fact that the cushioned bathroom articles known to the prior art are less attractive and considerably more expensive to fabricate than conventional bathroom articles, with a consequent large price differential at the retail level. Typical of the prior art cushioned bathroom articles and methods of making the same are those shown in the patent to Winfield, U.S. Pat. No. 3,816,234. In the Winfield patent, the composite structure is formed by first constructing a foam member in the general shape of the desired bathroom articles by assembling precut foam sheets. Then, a fiberglass-reinforced base is formed by applying polyester resin and glass fiber sheets to outer surfaces of the foam member in a conventional hand lay-up process. Thereafter, a finishing foam layer is applied to the inner surfaces of the foam member, the finishing layer being in the form of a putty and serving to mask imperfections and seams in the foam member. Then, a flexible polymeric layer is constructed by spraying or otherwise applying a vinyl resin to the finishing layer. One skilled in the art can readily appreciate that this process involves much hand labor, resulting in a bathroom article which is quite expensive to manufacture.
Another reason for the relatively high cost of cushioned bathroom articles made by prior art methods is the high incidence of production of articles which are defective by reason of their having large voids, or air spaces, in the foam layer. This is a particularly severe problem in articles wherein the foam layer is formed in situ with a self-foaming resin. Since the foam is cured in situ, the formation of such voids cannot be detected, and thus prevented, during fabrication of the article. The resulting cushioned article typically has areas of uneven texture and strength, and may in some cases exhibit warpage and distortion of the cushioned surface of the article. Typically, the outer vinyl coating is not sufficiently thick or strong to mask even relatively small voids. This problem results in a relatively high rejection rate for bathtubs made by such a process, with the result that the cost of producing bathtubs by such a method is increased accordingly.
It is therefore an object of this invention to provide a method of making an improved cushioned bathroom article.
It is another object of this invention to provide such a method of making an improved cushioned bathroom article which is formed of a laminar structure having a composite, flexible polymeric skin, a base and a cellular foam sandwiched between the flexible polymeric skin and the base, with the foam being formed by an in situ foaming process. It is also an object to provide a method of making such an article whereby the formation of voids in the cellular foam is minimized and whereby the adverse effects of such voids, in the event they do form, are also minimized.
It is yet another object of this invention to provide a method for constructing cushioned bathroom articles which significantly reduces the amount of hand labor involved and also reduces the rejection rate for the produced articles, thereby resulting in cushioned bathroom articles which are comparable in cost to that of conventional bathroom articles.